Epilepsy and EEG findings in patients with FMR1 gene mutation

We have analysed family history, clinical presentation, EEG findings
and results of molecular analysis in 23 patients with an amplification
in the FMR-1 gene. In fifteen (15/23 or 65.2%) patients EEG abnormaliteis
were found. In eight patients with fragile X syndrome (8/23 or 34.8%)
EEG patterns were epileptogenic. Five (5/23 or 21.7%) had documented
seizures. They started between age 3 and age 8. In four instances
seizures were of partial type or partial with secondary generalisation,
while only one patient had primary generalised grand mal epilepsy.
In three patients without epilepsy particular epileptogenic pattern
in form of centrotemporal focal spikes was found. In remaining seven
(7/23 or 30.4%) patients unspecific EEG abnormalities were noted.
Epilepsy was recorded only in males with distinct clinical presentation
and full mutation. Mosaic carriers as well as females with full mutation
that can be also considered as mosaics because of the X- inactivation
pattern, had milder clinical symptoms, no seizures or characteristic
EEG pattern. All points to the conclusion that the development of
seizures and characteristic EEG pattern in individuals with fragile
X syndrome is influenced by genotype modifications such as mosaicism
or metilation status, but probably also by additive effect of other
genes predisposing to seizures and by stochastic factors.

About us

Journal PAEDIATRIA CROATICA is the official journal of the Croatian Pediatric Society and Croatian Society of School and University Medicine. The editor is Children's Hospital Zagreb. It is published four times per year by Children's University Hospital Zagreb, Klaićeva 16, HR-10000 Zagreb, Croatia.Practicing pediatricians, pediatric subspecialists, neonatologists, family physicians, and other health care professionals that have children in their care.